The Microchip dspic33f is used for this Self Balancing Robot that chayben from Australia put together. Bluetooth modules are used to achieve communication link between the robot and the computer running Matlab. On the computer you are able to see the many tiny changes that are needed to keep the robot upright. The stacked round disk PCB design looks and works great in this design.
“Processor: Microchip dspic33f
Sensor: bma180 & itg3200
Sensor Fusion: modified complementary filter
Controller: PID
Motors: DC motors with Quadrature Encoder (not yet utilised)
Telemetry Module: Bluetooth to UART “